Electrical connector



May 14, 1940- H. K. KRANTz Y 2,200,794

ELECTRICAL CONNECTOR Filed May 8, 1957 2 Sheets-Sheet l /N VEN T10@HKKRANTZ' *ATTORNEY May 14, 1940.

H. K. KRANTZ 2,200,794

ELECTRIGAL CONNECTOR Filed May 8. 1937 2 sheets-sheet 2 Brag- WQ@ArToPA/Ey Patented May 14,1940 v l l l vUNITI-:o STATES PATENT formel.;

ELECTRICAL coNNEc'ron Hubert4 K. Krantz, Hempstead, N. Y., assignor toBell Telephone Laboratories, Incorporated, New

York, N. Y., a. corporation of New York Application May s, 1931,Soncino. 141,429

zclaims. (ci. 11a-1324) This invention relates to electrical connectorsFig. 4 is a cross-sectional view taken on linel fory interconnectinglconductors having motion 4-4 of Fig. 3; Y l relative to each other.Fig.' 5 is a side View of a telephone handset Its object is to produce adevice of this charpartly in section showing a. modicatlon o! the 5acter which will provide a low-friction electrical1 connector shown inFig. ,1; A y 5 4 connection'which is non-microphonic. Fig. 6 vis a frontview of the modiication The electrical connector of this inventioncomshown in Fig. 5 showing the coverV plate with prises relativelymovable conductors, one of these portions cut away; l conductors beingsuiliciently flexible to conform j Fig. 7 is a' longitudinal section ofthe handset to the surface of the `other conductor and slidtaken on line1-1 of Fig. 5;`

ably embracing such conductor. Fig. 8 is a cross-sectional' view takenon line The invention is particularly well adapted `for 8-8 of Fig. 5;use with cords associated with telephone appara.- ,-Fig. 9 is an. endview of the rotor and stator tus; for example, handsets, although it hasmany 4contact elements, the support for the iiexible other applications.Heretofore numerous atcontact element being shown in section;

tempts have been made to prevent the twisting Fig. 10 is a view showingthe rotor and stator of cords in handsets by the use of devices knowncontact elements in engaged relation;

as sswivel connectors. While such connectors Fig. 11 is a viewsimilarvto. Fig. 9 showing one have been found to be satisfactory in sofar as of the contact elements modined; and preventing the twisting ofthe cord is concerned, Fig. 12 is a view showing the modified contact $0it was found that objectionable microphonic element in engaged relationwith its associated noises were generated in the telephone talkingcontacts. l

circuit during the relative movement of the ro- .Referring t0 Figs. 1, 2and 3, the 60rd wires tor and stator elements of the connector, and Wl,W2 .and W3 are electrically Connected t0 that such noises were due tothe constant changes bushings 2l, 22 and 23'th10ugh terminals 3|. 32 25in resistance of the contacting area between these and 33 by screws 34.35 and 33. reSDeCtively. the two elements irrespective `0f the accuracy'at bushings 2|. 22 and 23 being insulated from 65011 which thesecontacting surfaces were made. other by concentrically disposedinsulating The invention, for purposes of illustration, is sleeves 31and 38.

shown as'embodied in aA telephonelhandset, and The conducting bushing 23iS fOrmed integrally 30 the connector is shown within the handset. Inwith a disc portion 39 which is screw-threaded this embodiment, anexible conductor slidably fOr engaging a rod 40 formed or welded to theembraces a cylindrical contact member. The conducting DOltOn-L WhichServes for receiv- 1 embracing conductor being flexible and tensioneding the SCIEW 33 fOl electrically-Connecting the 35 conforms exactlywith the periphery of the cylinwireW3 to the bushing 23. An insulatingpiece 35 drical contact member during the rotation of '42 is providedfor insulating the sleeve 22 from said member caused by relativemovement bethe end of conducting portion 4l and this'intween the handsetand the cord. The low-frie- V- sulating piece cooperates with bushing23-for tion vcharacteristic of the connector prevents holdingthebushings 2| and 22 and their insutwisting of the lcord and thenon-microphonic lating sleeves in assembled relation, counter nuts, 40

characteristic prevents the generation of noises as43, being providedfor preventing the loosenin the telephone talking circuit. ing ofconducting-bushing 23 on the rod 40.

Other novel features and advantages ofthe in# A collar 44l secured onthe rod-4l) engages a vention will appear. from the followingdescripforked member 45 and cooperates therewith 45 tion and by theclaims appended thereto, refer'- for holding thestator assembly thusformed 45V ence being had to the accompanying drawings againstlongitudinal movementin the telephone in which: l handle 46, the forkedmember 45, being secured Fig. l is a side view of a telephone handset byascrew 41 engaging a bushing 26v embedded showing the handle and anumber of operating in the handle. parts in section; A The bushings 2|,22 and 23 are insulatedv 111.50

Fig. 2 is a front view of the telephone handset end-to-end relation bydisc members 49 and 50 shown in Fig. l showing a cover plate with porand'these disc members cooperate' with disc tions cut away; members 5l and52, shown in Flg..3, for holding Fig. 3 is a longitudinal section of thehandset spirally wound conductors 53, 54 and 55 against taken in line3-3 of Fig. l; sldewise movement on the conducting bushings 2| 22 and 23and in engaged relation with the inner peripheries of conducting rings6|, 62 and 63 which are lembedded in the handle 46, and have connectionswith the receiver R and the transmitter T of the handset throughconductors y 64-65 and 66-61 embedded in the handle and convolutions ofthe conducting members 53, 54

and 55 likewise frictionally engage their associated rings 6|, 62 and 63`so that the handset 46 is free to rotate relative to the cord C withouttwisting it, the spiral conductors 53, 54 and55 remaining positively incontacting relation with their bushings 2|, 22 and'23, and rings 6|, 62and 63, respectively.

In the connector illustrated in Figs. 1 to 4, due to the fact that thespiral conductors 53, 54 and 55 are lmade of resilient metallic strip,maximum contact surface is maintained during the relative movement ofthe handset with respect to the telephone cord irrespective of the minorirregularities and eccentricities of the surfaces of the bushings andrings, andtherefore microphonic noises in the telephone circuit areeffectively avoided.

The plate 10, which is held securely on the handle 46 by screws 1| and'|2, shown in Figs. 1

and 2, is provided for preventing the entrance `of dust and otherforeign particles into the cavity Y formed `in the handle and onto thecontact devices, while facilitating access to the operating parts of theconnector for adjustments and repairs. Instead of using screws to fastenthe plate 10 on the handset it may be sealed thereto.

In the modification of the invention, shown in Figs. 5 to 10, inclusive,ilexible, irresilient wires 8|, 82 and 83, preferably stranded, arewound over bushings 2|, 22 and 23 and the ends of these wires aresecured to the free ends of spring arms 9|, 92 and 93, insulated fromeach other and secured by a screw 95 in a pile-up arrangement on ashoulder portion 94 in the cavity Y formed in the handle 46.

In the modification shown in Figs. 11 and 12, the exible, irresilientwires 8|, 82 and 83 are wound around the bushings 2|, 22 and 23 and theends of the wires are secured to their spring arms 9|, 92 and 93, in amanner similar to the modication shown in Fig. 5. On the end of rodf40is screwed an end-piece 96 which serves for holding bushings 2l, 22 and23 in assembled relation and a pin 91, shown in Fig. '1, is provided forpreventing the loosening 'oi' end-piece 96 on the rod 48, this end-piecebeing provided with a spherical portion 98 disposed in engaged relationwith two `complemental curved arms 99 and |80, shown in Figs. 5 and 7,for preventing longitudinal movement of the bushing assembly relative tothe handle 46 while permitting the free rotary movement of the handsetwith respect to the cord.

t The connections between the` spring arms 9 I, 92

and 93to the conducting wires 64, 65, 66 and 61,'

which are embeddedin the handle, are effected by terminals carried bythe spring arms, and screws IM, |02 and |03 engaging respective bushingsembedded in the handle 46 to which these conductors are secured, as bywelding,

In these modifications, the tension of, each spring arm 9|, .92 and 93issuch as to permit relative movement between the bushings 2| 22 and 23forming the stator element and the wires 8|, 82 and 83 without causingthe twisting of the cord, 'the wires 8|. 82 and 83 being suiliciently'flexible and irresilient to conform at all times with the periphery ofthe bushings, irrespective oi' minor surface unevenness andeccentricities of these bushings, lthus maintaining positive contactbetween the stator-and rotor and effectively preventing'microphonicnoise in the talking circuit of the telephone line. l

- While the invention has been illustrated as applied to a connectorthat will prevent the twisting of the extension cords of telephonehandsets,

vit should be understood that its application is not so limited,but itis equally applicable to other electrical devices, not .necessarily of aportable nature or equipped with cordage but wherein electricalconnection is made between conducting elements capable of motionvrelative to each switching apparatus, etc.

What is claimed is: l. A non-microphonic connector device for the cordof a telephone handset, said handset having a longitudinal bore adjacentthe transmitter end thereof, a multicontact plug having insulated ringscontiguous to each other longitudinally loosely engaging the bore, meanscarried by the handset cooperating with means carried by said plug forpreventing longitudinal movement o'f said plug relative to the handsetand holding it -in centered position relative to the bore for permittingfree rotation therein, a plurality of con nectorssecured to the handsetone for each of said rings, and flexible conductors connectingrespectively saidrings to' said connectors, the ilexible conductorshaving portions disposed concentric to and frictionally engagingsubstantially the in said handset and connecting said rings to the'transmitter and receiver at the ends of the handset, a plug mounted forrotary movement in the bore of the handset, said plug consisting o f acentrally disposed conductor member formed with a sleeve .portion at oneend thereof, a plurality other, such as, for instance, cord reels,'machine of concentrically disposed insulating-and conducting bushingsmounted on .said conductor member, said conductor member and saidconducting bushings-having means for securing the wire conductors of thetelephone' cord thereto, a second sleeve mounted4 on the end o'f saidcentrally disposed conductor member opposite the first-mentioned sleeveportion, conducting springs frictionally engaging said rings, metallicbushings and the last-mentioned sleeve for establishing electricalconnections between the conducting wires ofthe cord and the transmitterand receiver of the handset and means secured to said centrally disposedconductor engaging means secured to the handset for holding said plugagainst longitudinal movement in the `bore of the handset.

' HUBERT K. KRANTZ.

